jabbrv-ltwa-all.ldf jabbrv-ltwa-en.ldf The relationship between saxicolous lichen communities and the characteristics of lichened rock debris on patterned ground was investigated in the Daisetsuzan Mountain Range, Hokkaido, Japan. A total of 900 samples were collected from 18 sites, and 45 lichen taxa were identified. The number of species per piece of rock debris, β-diversity at each site, and species distribution patterns were influenced not only by the size and surface area of the rock debris but also by its density and shape. High-density and flat-shaped rock debris (which is not easily rotatable) located at the borders of patterned ground supported lichen survival, whereas smaller, less dense rock debris hindered growth due to repeated solifluction. Lichen communities of each site exhibited high β-diversity, even among adjacent patterned grounds, suggesting that random colonization processes play a key role in determining community structure.